5. The subsequent steps are identical with those described under the Enrichment method (see page 428 to 431; Steps 8 to 18). _Alternative Methods._-- A few of the older methods for the isolation of the members of the coli-typhoid groups are referred to but they are distinctly inferior to those already described. (A) The Carbolic Method: 1. Take ten tubes of carbolised bouillon (_vide_ page 202) and number them consecutively from 1 to 10. 2. Inoculate each tube with a different amount of the water sample or suspension, as in the previous method. 3. Incubate aerobically at 37° C. 4. Examine the culture tubes after twenty-four hours' incubation. 5. From those tubes which shows signs of growth, pour plates in the usual manner, using carbolised gelatine (_vide_ page 202) in place of the ordinary gelatine, and incubate at 20° C. for three, four, or five days as may be necessary. 6. Subcultivate from any colonies that make their appearance, and determine their identity on the lines laid down in the previous method. (B) Parietti's Method: 1. Take nine tubes of Parietti's bouillon (_vide_ page 202)--i. e., three each of those containing 0.1 c.c., 0.2 c.c., and 0.5 c.c. of Parietti's solution respectively. Mark plainly on the outside of each tube the quantity of Parietti's solution it contains. 2. To each tube add a different amount of the original water, or of the suspension, and incubate at 37° C. 3. Examine the culture tubes after twenty-four and forty-eight hours' incubation, and plate in nutrient carbolised or potato gelatine from such as have grown. 4. Pick off suspicious colonies, if any such appear on the plates, subcultivate them upon the various media, and identify them. (C) Elsner's Method: This method simply consists in substituting Elsner's potato gelatine (_vide_ page 204) for ordinary nutrient gelatine in any of the previously mentioned methods. (D) Cambier's Candle Method: Treat a large volume of the water sample by the concentration method (_vide_ page 434). 1. Remove the rubber stopper from the mouth of the filter candle, introduce 10 c.c. sterile bouillon into its interior, and emulsify the bacterial sediment; replug the mouth of the candle with a wad of sterile cotton-wool. 2. Remove the filter candle from the filter flask and insert it into the mouth of a flask or a glass cylinder containing sterile bouillon sufficient to reach nearly up to the rubber washer on the candle. 3. Incubate for twenty-four to thirty-six hours at 37° C. 4. From the now turbid bouillon in the glass cylinder pour gelatine plates and incubate at 20° C. 5. Subcultivate and identify any suspicious colonies that appear.